As a DL PM, you should be able to waitlist for complimentary upgrades, which are processed at (for you, I believe) the 48-hour-out mark. You'll be behind all MVPGs and MVPs, though. Still, it's a better chance than the paid day-of-departure upgrades. (EDIT: DISREGARD--BENEFIT STILL PENDING)

To the OP: one trick is to view the full plane seat map while logged in as MVP/G. Pay special attention to the teal seats (especially the second exit row [the first exit row is always blocked] and row 6). If they're mostly empty (and F is empty, too), your chances of upgrading should be pretty good, as you'll be one of the first elites to book that flight and should be near the front of the waitlist queue. If row 6 and the rear exit row and half of the other teal seats are full and there's only two empty F seats--skip that flight!